Ultraviolet (UV) lamps are known for curing inks, adhesives, paint and similar coatings. Normally, such coatings would require hours to dry and harden but UV light usually causes molecular cross-linking and hardening within a few seconds. Because these coatings are usually applied to two-dimensional surfaces, it is advantageous to scan the surfaces with a UV beam tube that has a lengthwise or linear axial extent similar to a fluorescent tube so that the surface can be scanned in a series of parallel adjacent stripes. To concentrate the emission of such a linear tube, a parabolic or elliptical housing is used to reflect light from the tube over an extent that can be as narrow as a line for maximum concentration or a stripe parallel to the tube for a more useful surface scanning concentration.
In U.S. Pat. No. 6,739,716 to D. Richards, a UV lamp axial tube is shown having a reflector with two symmetrical parts on opposite sides of the tube. The reflector can focus UV light to a desired position such as a stripe of variable width.
One of the problems occurring with UV lamp axial tube reflectors is that both the lamps and reflectors reach high temperatures because the reflectors are used in closed proximity to surfaces being treated. Under such circumstances, heat can be trapped within the reflector causing a risk of burning the surface being treated or deformation of the lamp tube or the reflector itself.
In U.S. Pat. No. 5,003,185 to Burgio, Jr. a reflector assembly for a tube is shown to have both an air and water conduit extending through a reflector block for cooling purposes. Air is driven by blowers through ports in the reflector structure, while water is used to remove heat from the block. While this heat removal structure is useful, it is more suited to fixed positioning where a surface to be treated moves past the reflector structure.
A problem that has occurred in recent years is that graffiti is ubiquitous in certain urban areas. Graffiti abatement often consists of applying solvents, paint or other coatings to dissolve or cover the graffiti. Such surface treatments require curing assemblies of the prior art are not adapted for portable use.
An object of the invention was to devise a reflector structure for UV lamp axial tubes that was sufficiently light weight that the reflector could be moved with ease over a wall or surface being treated yet had adequate cooling for safety.